1. Field of the Invention
The present invention is related to an electrical connector, especially to a straddle connector which is straddle-mounted on an edge of a printed circuit board wherein the terminals of the connector connect to pads disposed at either one or both sides of the printed circuit board.
2. Description of the Related Art
Printed circuit boards play an important role in the computer industry. Currently, most electrical or electronic functions are achieved on a motherboard, which is one kind of a printed circuit board which is installed inside of every computer. Many electronic components, such as a CPU, memory etc., and peripheral devices, like a CD ROM, a hard disk etc., must be connected to the motherboard before they work. However, the necessary connections take up a large amount of space, which complicates the layout of the motherboard and reduces the available space on the motherboard. Therefore, considering the corresponding location and size of some electronic components and the motherboard, some of the supporting connectors are straddle-mounted on the edge of a motherboard or a daughter board connected thereto to save space on the motherboard and to facilitate the installation of some larger peripheral devices. Two known contact arrangements for connectors to be straddle mounted on a printed circuit board can be considered for adoption. Chen et al. U.S. Pat. No. 5,292,265 and Long U.S. Pat. No. 5,893,764 both introduce connectors having two rows of contacts where contacts of one row are engaged on one side of the printed circuit board while contacts of the other row are engaged on the opposite side. A curved tail of every contact is disposed for engaging with a corresponding pad mounted on the printed circuit board due to the difference between the thickness of the printed circuit board and the distance between the two contact rows. These vulnerable contact tails without auxiliary guiding means or fixtures cause problems before the connector is straddle mounted on the printed circuit board. Tor et al. U.S. Pat. Nos. 5,823,799 and 5,971,775 show all the contacts are soldered onto only one side of the printed circuit board, no matter how many rows of contacts the connector has. This type of contact tail arrangement is more easily made and protected because it avoids unnecessary collision in the mounting process. But the space on the edge side of the printed circuit board is still limited, which results in the corresponding soldering pads on the printed circuit board being so close to each other that the soldering process is complicated. The above-mentioned two arrangements may be adopted at the same time when the number of contacts is increased, but the size of the connector is shortened, following one current design tendency. Therefore, high density connectors with multi rows of contacts have been introduced to meet the need of high speed transmission. Schmidgall et al., European Patent Application No. 01126552, shows a connector with three rows of contacts, which straddle mounts on a printed circuit board by soldering two rows of contacts on the same side of the printed circuit board. The row of contacts that is farther from the edge surface of the printed circuit board than the others needs longer and specially bent tails to be engaged with the printed circuit board. Dense soldering pads cause higher cost and more difficult soldering, and well designed guiding and fixing means may be needed to protect contact tails from colliding and damaging each other.
Furthermore, crosstalk is usually a concern in high density connectors, especially for high speed transmission. Grounding means is then added to surround and shield contacts from each other in order to get higher electrical performance. Cohen et al. U.S. Pat. No. 6,152,742 and Grabbe et al. U.S. Pat. Nos. 5,320,541 and 5,813,871 all introduce a straddle mount connector having a grounding plate disposed between two rows of contacts. The grounding plate has tails extending near tails of contacts and being soldered onto the same edge of the printed circuit board to establish electrical grounding paths. Obviously, there are many more tails, including both signal and grounding tails, than are needed to connect with the printed circuit board. Cost is high and it takes time to arrange these connector tails and soldering pads on the printed circuit board, and space on the printed circuit board is limited. And specialized parts, like nonstandard holes in the printed circuit board, as shown in the above patents, are always expensive and time consuming. In particular, tails of the grounding plate and tails of contacts cannot be spaced far enough away from each other due to the limited space. Shorting circuiting between contacts may result, because tails of the grounding plate may accidentally collide with the contact tails due to the strong straddle mount force required when mounting the connector to the printed circuit board, and the high density arrangement of the connector tails. To avoid such accidental collisions due to the use of so many long tails, an expensive insert molding method may be necessary to assemble the contacts and the grounding plate with the connector housing.
Therefore, an object of the present invention is to provide a straddle mount connector having an adjustable insulated separating portion to isolate terminal tail ends and legs of the grounding member from each other to reduce the potential of accidental collision while they are installed onto the printed circuit board.
Another object of the present invention is to provide a straddle mount connector having an adjustable insulated separating portion to properly isolate terminal tail ends from legs of the grounding member at all times, even though the connector may be installed onto at least two printed circuit boards each having a different board thickness from the other.
Another object of the present invention is to provide a straddle mount connector having an adjustable insulated separating portion to assemble terminals and the grounding member mechanically rather than using the expensive process of insert molding when tail ends of terminals and legs of the grounding member vary to be mounted on at least two different printed circuit boards.
To obtain the above objects, an electrical connector straddle-mounted on an edge of a printed circuit board includes an insulative housing having an elongated groove for mating. A plurality of receiving channels each used to receive a support subassembly is formed adjacently to and communicated with the mating groove. The support subassembly includes a plane-like base having a plurality of parallel arranged passageways formed on one surface of the base and a protrusion formed on the other. Pin-like signal terminals are inserted into the passageways respectively along the surface of the base and a plate-like grounding member is installed abutting against the other surface of the support subassembly to be fixed on the protrusion. A bar portion transversely protruding from the surface of the base having passageways, several holding portions formed in a hook shape on one edge side of the grounding member and the protrusion are all used to stop the insertion of the support subassembly when it is assembled into the housing. Every terminal includes an engaging end exposed to the mating groove once the terminal is inserted into the housing accompanying the support subassembly, and a tail end extending out of the receiving channel in a suspended status. And the grounding member includes a plurality of contacting legs extending away from the grounding member for a predetermined distance and being suspended similar to the tail end of every terminal.
Specifically, a hinge portion with a thinned area on the base and defines an elongate notch thereon. The hinge portion is a hinge area used to facilitate relocating the separating portion relative to the base. Therefore, the separating portion of the base can always be positioned between the tail ends of terminals and the contacting legs of the grounding member to electrically insulate them from each other though the shape of tail ends and contacting legs are changed to be mounted on another desired printed circuit board with a different thickness. And the separating portion can be moved for the ease of assembling every terminal and grounding member when they are put together to form the support subassembly being inserted into the housing.